/*
 * contrib/pg_trgm/trgm.h
 */
#ifndef __TRGM_H__
#define __TRGM_H__

#include "access/gist.h"
#include "access/itup.h"
#include "storage/bufpage.h"

/*
 * Options ... but note that trgm_regexp.c effectively assumes these values
 * of LPADDING and RPADDING.
 */
#define LPADDING        2
#define RPADDING        1
#define KEEPONLYALNUM
/*
 * Caution: IGNORECASE macro means that trigrams are case-insensitive.
 * If this macro is disabled, the ~* and ~~* operators must be removed from
 * the operator classes, because we can't handle case-insensitive wildcard
 * search with case-sensitive trigrams.  Failure to do this will result in
 * "cannot handle ~*(~~*) with case-sensitive trigrams" errors.
 */
#define IGNORECASE
#define DIVUNION

/* operator strategy numbers */
#define SimilarityStrategyNumber        1
#define DistanceStrategyNumber            2
#define LikeStrategyNumber                3
#define ILikeStrategyNumber                4
#define RegExpStrategyNumber            5
#define RegExpICaseStrategyNumber        6
#define WordSimilarityStrategyNumber    7
#define WordDistanceStrategyNumber        8

typedef char trgm[3];

#define CMPCHAR(a,b) ( ((a)==(b)) ? 0 : ( ((a)<(b)) ? -1 : 1 ) )
#define CMPPCHAR(a,b,i)  CMPCHAR( *(((const char*)(a))+i), *(((const char*)(b))+i) )
#define CMPTRGM(a,b) ( CMPPCHAR(a,b,0) ? CMPPCHAR(a,b,0) : ( CMPPCHAR(a,b,1) ? CMPPCHAR(a,b,1) : CMPPCHAR(a,b,2) ) )

#define CPTRGM(a,b) do {                \
    *(((char*)(a))+0) = *(((char*)(b))+0);    \
    *(((char*)(a))+1) = *(((char*)(b))+1);    \
    *(((char*)(a))+2) = *(((char*)(b))+2);    \
} while(0);

#ifdef KEEPONLYALNUM
#define ISWORDCHR(c)    (t_isalpha(c) || t_isdigit(c))
#define ISPRINTABLECHAR(a)    ( isascii( *(unsigned char*)(a) ) && (isalnum( *(unsigned char*)(a) ) || *(unsigned char*)(a)==' ') )
#else
#define ISWORDCHR(c)    (!t_isspace(c))
#define ISPRINTABLECHAR(a)    ( isascii( *(unsigned char*)(a) ) && isprint( *(unsigned char*)(a) ) )
#endif
#define ISPRINTABLETRGM(t)    ( ISPRINTABLECHAR( ((char*)(t)) ) && ISPRINTABLECHAR( ((char*)(t))+1 ) && ISPRINTABLECHAR( ((char*)(t))+2 ) )

#define ISESCAPECHAR(x) (*(x) == '\\')    /* Wildcard escape character */
#define ISWILDCARDCHAR(x) (*(x) == '_' || *(x) == '%')    /* Wildcard
                                                         * meta-character */

typedef struct
{
    int32        vl_len_;        /* varlena header (do not touch directly!) */
    uint8        flag;
    char        data[FLEXIBLE_ARRAY_MEMBER];
} TRGM;

#define TRGMHDRSIZE          (VARHDRSZ + sizeof(uint8))

/* gist */
#define BITBYTE 8
#define SIGLENINT  3            /* >122 => key will toast, so very slow!!! */
#define SIGLEN    ( sizeof(int)*SIGLENINT )

#define SIGLENBIT (SIGLEN*BITBYTE - 1)    /* see makesign */

typedef char BITVEC[SIGLEN];
typedef char *BITVECP;

#define LOOPBYTE \
            for(i=0;i<SIGLEN;i++)

#define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
#define GETBITBYTE(x,i) ( (((char)(x)) >> (i)) & 0x01 )
#define CLRBIT(x,i)   GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
#define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITBYTE ) )
#define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITBYTE )) & 0x01 )

#define HASHVAL(val) (((unsigned int)(val)) % SIGLENBIT)
#define HASH(sign, val) SETBIT((sign), HASHVAL(val))

#define ARRKEY            0x01
#define SIGNKEY            0x02
#define ALLISTRUE        0x04

#define ISARRKEY(x) ( ((TRGM*)x)->flag & ARRKEY )
#define ISSIGNKEY(x)    ( ((TRGM*)x)->flag & SIGNKEY )
#define ISALLTRUE(x)    ( ((TRGM*)x)->flag & ALLISTRUE )

#define CALCGTSIZE(flag, len) ( TRGMHDRSIZE + ( ( (flag) & ARRKEY ) ? ((len)*sizeof(trgm)) : (((flag) & ALLISTRUE) ? 0 : SIGLEN) ) )
#define GETSIGN(x)        ( (BITVECP)( (char*)x+TRGMHDRSIZE ) )
#define GETARR(x)        ( (trgm*)( (char*)x+TRGMHDRSIZE ) )
#define ARRNELEM(x) ( ( VARSIZE(x) - TRGMHDRSIZE )/sizeof(trgm) )

/*
 * If DIVUNION is defined then similarity formula is:
 * count / (len1 + len2 - count)
 * else if DIVUNION is not defined then similarity formula is:
 * count / max(len1, len2)
 */
#ifdef DIVUNION
#define CALCSML(count, len1, len2) ((float4) (count)) / ((float4) ((len1) + (len2) - (count)))
#else
#define CALCSML(count, len1, len2) ((float4) (count)) / ((float4) (((len1) > (len2)) ? (len1) : (len2)))
#endif

typedef struct TrgmPackedGraph TrgmPackedGraph;

extern double similarity_threshold;
extern double word_similarity_threshold;

extern uint32 trgm2int(trgm *ptr);
extern void compact_trigram(trgm *tptr, char *str, int bytelen);
extern TRGM *generate_trgm(char *str, int slen);
extern TRGM *generate_wildcard_trgm(const char *str, int slen);
extern float4 cnt_sml(TRGM *trg1, TRGM *trg2, bool inexact);
extern bool trgm_contained_by(TRGM *trg1, TRGM *trg2);
extern bool *trgm_presence_map(TRGM *query, TRGM *key);
extern TRGM *createTrgmNFA(text *text_re, Oid collation,
              TrgmPackedGraph **graph, MemoryContext rcontext);
extern bool trigramsMatchGraph(TrgmPackedGraph *graph, bool *check);

#endif                            /* __TRGM_H__ */
